Conventionally, non-ionic surfactants such as polyoxyethylene alkyl ether and sorbitan fatty acid partial ester have been mainly used for emulsification in the field of cosmetics.
Since such surfactants inevitably raise irritation to the skin in greater and lesser degrees, attempts were made to evade such irritation by decreasing the amount of surfactants as much as possible or carrying out the emulsification without any surfactant depending on the situation. However, such attempts are not necessarily satisfied because there is a tendency to cause problems in the uniformity and stability of emulsion.
On the other hand, it has been proposed to prepare an emulsion which is highly safe to the skin by using, as an emulsifier, components come from a natural substance such as saponin, lecithin and enzyme-hydrolyzed stevioside, and a part of such proposals has been in practical use. However, the use of such components hardly adequate from viewpoints of emulsion stability, feeling when applied to the skin and easiness of manufacturing. Therefore, it is desired to develop a new emulsifier come from a natural substance which solves such disadvantages.
The above-mentioned biological safety is commonly required not only for emulsifier but also for all of other cosmetic components. If active components including a brightening component and a component for preventing skin aging could be found, which has both effectiveness and safety, it could be said that the active components have remarkably excellent utility.
As the result of diligent studies relating components to be used for cosmetics, especially emulsifier, in order to provide an agent having a high safety come from a natural substance, the inventors have found that the fermented rice is useful as a base material such as emulsifier and emulsion stabilizer, because fermented rice obtained by fermenting rice with lactic acid bacteria has good emulsifying effect, good emulsion-stabilizing effect and colloid stabilizing effect, and the fermented rice is highly safe to human body due to its less toxicity and less irritant to the skin owing to its rice origin, and the present invention has been accomplished. The inventors unexpectedly have found that the fermented rice is also useful as an agent for exhibiting beautifying effect of cosmetic treatment due to its excellent brightening and caring effects on the skin, and improving the hair texture.